1. Field of the Invention
The present invention relates to an optical module used for an optical communication system such as an optical local area network (LAN) or an optical data link using light as an information transmission medium.
2. Related Background Art
Japanese Patent Laid-Open No. 2-271308 discloses a conventional optical module. This conventional optical module comprises a cylindrical sleeve. The sleeve consists of a metal such as stainless steel. One end of the sleeve has an opening for accommodating an optical operation element. The other end of the sleeve also has an opening capable of accommodating at least a part of an optical fiber positioning ferrule arranged at the distal end of a connector plug. The optical operation element is fixed in this sleeve with an adhesive or the like. The outer wall of the sleeve has a flange for fixing the sleeve itself.
The conventional optical module further includes a package body for supporting a circuit board. A support plate for fixing a sleeve is fixed in the package body with an adhesive or the like. The flange of the sleeve in which the optical operation element is mounted is adhered and fixed to the support plate. Terminals extending from the bottom portion of the optical operation element are electrically connected to a constituent element (an electronic component such as resistor, a bare chip IC, etc.) of the circuit board mounted on the package main body. An electrical signal output from this electronic circuit is extracted outside the optical module through a plurality of lead pins.
Japanese Patent Laid-Open No. 4-165312 discloses a structure for fixing a sleeve. In this reference, the outer wall of the sleeve has a flange for fixing the sleeve itself. The flange is clamped between a sleeve holder and a plate having a special shape, and the sleeve holder and the plate are fixed with rivets, so that the sleeve is firmly fixed to only the sleeve holder. In addition, the sleeve holder to which the sleeve is fixed with the plate and the rivets is fixed to a housing for accommodating the entire sleeve.